Honda Cylinder Head/Crankcase Anode Metal - 12155-ZZ5-010. Important: Quantity varies by engine.. BF40DK4 / BF50DK4: 2 required per engine. BF350A (Crankcase): 2 required. BF350A (Cylinder Head): 4 required. Help protect your Honda outboard from internal corrosion with the genuine Honda cylinder head and crankcase anode metal, part number 12155-ZZ5-010. These sacrificial anodes are designed to corrode first, helping reduce galvanic corrosion inside the engine and protecting more expensive internal surfaces in harsh marine conditions. Replacing worn anodes on schedule supports cooling efficiency and long-term reliability.. Key Features. Genuine Honda anode metal for internal corrosion protection. Designed for cylinder head and crankcase anode locations (by application). Sacrificial design helps protect internal engine components from corrosion. Ideal for preventative maintenance and routine corrosion control. OEM fit and function for compatible Honda applications. Fitment. Honda BF40DK4